diff --git a/interface/lib/classes/validate_domain.inc.php b/interface/lib/classes/validate_domain.inc.php
index d8c87e09f1d6f8b41cf6a0be6e6bf66058515f79..3555135eae028efd7163769ff41c6e6808500da9 100644
--- a/interface/lib/classes/validate_domain.inc.php
+++ b/interface/lib/classes/validate_domain.inc.php
@@ -135,6 +135,9 @@ class validate_domain {
 					foreach($directives as $directive) {
 						$directive = trim($directive);
 						foreach($regex as $r) {
+							if(trim($r) == '') {
+								continue;
+							}
 							if(preg_match(trim($r),$directive)) {
 								$blocked = true;
 								$blocked_line .= $directive.'<br />';